Abstract

The aim of this study was to analyze the intensity of contraction and the muscular coordination of one subject’s 14 trunk and shoulder muscles during the reception and throwing of a medicine ball (plyometric task), the standing cable chest press and the use of the Bodyblade® (flexible foil whose oscillation generates body vibrations and continuous unbalances). Muscular responses to controlled trunk loading and unloading were recorded, enabling a discussion about active spine stabilization. Our results indicate that trunk muscular activation is important to both stabilize the spine under sudden perturbations and to perform activities where the upper limbs handle and use objects. Coactivation of the trunk muscles was necessary to stabilize the spine against both the oscillations of the Bodyblade® and the reaction moment produced when pushing a heavy load in standing. In addition, the catch and throw of the medicine ball is a relatively complex activity that requires coordinated activation of muscles of the trunk and the limbs.